HTX-252 2-Meter Amateur FM Mobile Transceiver
(190-1127)                 Operation                  Faxback Doc. # 60180

A Quick Look At The Controls

Most of the controls on the transceiver have multiple functions.  The 
following charts should help you get a better idea of the function of each 
control.

Base Unit

Key/Control      Use it to:                      Use with the F + Key to:

OFF/VOL          Turn the transceiver on/off.    Reset the transceiver.
                 Adjust the volume.

SQ               Set the squelch level to block  N/A
                 weak signals.

REV              Reverse the repeater offset.    N/A     

VFO (T-SQ)       Set the transceiver to VFO      Set the tone squelch.
                 mode.

MR (MS)          Recall a frequency in memory.   Store a frequency in
                                                 memory.

Tuning Control   Change the frequency by the     Change the frequency by
                 set STEP value.                 1 MHz steps.

Push to Talk     Transmit by holding it down.    Change the transmitting
(PTT)            Press to store a setting.       power to high or low.

UP               Increase the frequency by the   Increase the frequency in
                 selected step value.            1 MHz steps.

DN               Decrease the frequency by the   Decrease the frequency by
                 selected step value.            1 MHz steps.

F (MHz)          Temporarily open the squelch.   N/A

CALL (STEP)      Recall the calling frequency    Set the frequency step.
                 memory.

SCAN (PRI)       Start and stop scanning.        Set the transceiver to
                                                 dual watch mode.

LOCK (SHIFT)     Lock and unlock the controls    Set the repeater offset.
                 except PTT, F, VOL, and SQ.

Alpha-Numeric    Enter numerical values and      N/A
Keys             DTMF control letters.

DTMF             Switch to DTMF control.         N/A

A Quick Look At The Display

1.  (FUNC) - appears when F key is pressed.

2.  (key symbol) - indicates the keypad is locked.

3.  (-) - indicates a negative repeater offset.

4.  (+) - indicates a positive repeater offset.

5.  (SCAN) - appears when the transceiver is scanning frequencies.

6.  (PRI) - indicates a priority frequency. 

7.  (T) - appears when Tone Squelch (CTCSS) is enabled for both
          transmission and reception.

8.  (T-SQ) - appears when Tone Squelch (CTCSS) is enabled for both 
             transmission and reception.

9.  (Alpha-Numeric Display) - shows frequency and operation feature
                              information.

10. (TX) - appears when the transceiver is transmitting.

11. (0-9) - shows the memory channel in use.

12. (BUSY) - appears when the transceiver receives a signal.

13. ([1][][3][][5][][7][][9][]) - indicates signal strength; the stronger
                                  the signal, the more boxes appear.

14. (ME) - appears when the frequencies and other station data are being
           stored or while scanning data in memory locations. 

Note: When you reset the transceiver, all display elements appear.  See
      "Resetting the Transceiver" in Faxback Doc. # 60183.

Operation

Turning The Transceiver On And Off

To turn on the transceiver, rotate VOL clockwise until it clicks. The last 
used frequency and other settings appear (the default frequency is 142.50
MHz, with a frequency step of 5 kHz/.005 MHz. To turn the transceiver off,
rotate VOL counterclockwise until it clicks.

Selecting Frequencies

To select a frequency in the VFO (variable frequency oscillator) mode, use
either UP or DN on the top of the microphone or the tuning control.

Using either method lets you step up or down in increments which you set 
using the Frequency Step option.  (See "Setting the Frequency Step" in 
Faxback Doc. # 60181.)

Rotating the tuning control changes the frequency by the value of the step 
you set.  You might want to set your preference for the step value before 
you make other settings.  Repeatedly pressing (or holding down) UP or DN 
also changes the frequency by the step value.  To change the frequency by 
1 MHz steps, press F so [FUNC] appears. Then repeatedly press or hold down 
UP or DN.

The displayed frequency is typically shown to two significant decimal 
places.  However, depending upon the selected frequency step, you might 
see a smaller number displayed to the right of the second place.  For 
example, 142.50(sub 75) lets you see the complete frequency in use if you 
select 12.5 kHz as your frequency step.

Receiving Transmissions

Follow these steps to receive standard transmissions.

1.  With the transceiver on, rotate SQ counterclockwise until you hear a
    hissing sound.  Then slowly rotate SQ clockwise just until the noise
    stops.

    Notes:  BUSY appears when the transceiver receives a standard 
            transmission or if the squelch is open.

            If the transceiver picks up unwanted and weak transmissions,
            rotate SQ clockwise to prevent the squelch from opening for 
            these transmissions.  If you want to hear weak transmissions, 
            rotate SQ counterclockwise.  When you do this, you might hear 
            hissing between transmissions. 

2.  Rotate the tuning control to select a frequency. 

3.  Set VOL to a comfortable listening level. 

Transmitting

There are two basic types of communication possible with this transceiver; 
radio-direct-to-radio (simplex) or radio-to-repeater-to radio (duplex).  
Simplex operation uses the same frequency to send and receive.  Duplex 
operation uses one frequency to transmit and another to receive.  For more 
information about duplex, see "Understanding Repeaters" below.

CAUTION:  It is illegal to transmit if you do not have at least a 
          Technician Class license issued by the FCC. 

Follow these steps to transmit.

1.  Select the desired frequency using control or UP/DN until you are
    within the transmit frequency range.

2.  Hold the microphone about 3 inches from your mouth.

3.  Hold down the ribbed transmit button on the side of the microphone,
    then speak slowly and clearly into the microphones. (TX) appears while
    you transmit and signal strength bars appear on the bottom to indicate
    the relative transmitting signal output.

    Note: If you try to transmit outside the transit frequency range, (E)
          appears instead of (TX) to indicate you are outside the 
          transmitting range. 

4.  Release the transmit button when you finish transmitting. 

Understanding Repeaters

Operating through a repeater, where you transmit on one frequency and 
receive on another, is called duplex operation.  Operating direct to 
another station, where you transmit and receive on the same frequency is 
called simplex operation.

A repeater is a station that receives a signal on one frequency (the input 
frequency) and then retransmits that signal on a different frequency (the 
output frequency).  Repeater antennas are typically located at the tops of 
tall buildings or on antenna towers, so a relatively low-power signal can 
reach the repeater. The repeater retransmits the signal at a higher power.  
This gives your transceiver the ability to communicate over a much greater 
range. 

To use a repeater, you must know the repeater's input and output 
frequencies.  Repeaters are usually identified by their output frequency. 
For example, a repeater that has an output frequency of 146.94 is referred 
to as "the 146.94 repeater."  To determine the input frequency, you must 
know the frequency offset (typically 600 kHz for the 2-meter band)and the 
offset direction (+ if you add 600 kHz to the output, or - if you subtract 
600 kHz from the output).

Whether the offset is positive or negative depends on:

  Which part of the band the repeater operates on.

  Local convention.

  Proximity of repeaters using the same two frequencies.

To determine the offset and the direction, obtain a copy of The ARRL 
Repeater Handbook (available at your local RadioShack store or directly 
from the ARRL).  That book lists the locations of repeaters as well as 
their frequency and offset information. 

A (+) above the displayed frequency indicates a positive offset, while a 
(-) above the frequency indicates a negative offset. If neither (+) nor
(-) appears, the transceiver is set for simplex operation.

Setting The Repeater Offset Frequency

Note:  This setting affects only the VFO mode.  If you saved a repeater 
       offset in a memory, that setting is not affected. 

1.  Press F + SHIFT (LOCK).  The offset frequency and (-) appear. 

2.  While the offset frequency appears, rotate the tuning control or
    repeatedly press UP or DN until the desired offset appears.  The
    transceiver's default repeater offset is 600 kHz, which appears as 
    0.60 (MHz).  You can select a value from 100 kHz to 8.000 MHz.

3.  Press PTT to store the setting or wait 5 seconds.  The selected value
    is stored and the operating frequency appears.

Setting The Repeater Offset Direction

1.  Set an offset frequency.

2.  Repeatedly press F + SHIFT (LOCK) to change the current offset
    direction ((+) above, (-) below or neither for simplex or non-repeater
    operation).

3.  Press PTT to store the setting or wait 5-seconds.  The selected value 
    is stored and the operating frequency appears.

Reversing The Transmit And Receive Frequencies

To swap the input and output frequencies, press REV. For example, if you 
have set the transceiver to repeater operation on 146.94 MHz with a 
positive offset of 600 kHz, the transceiver would normally receive on 
146.94 MHz and transmit on 147.54 MHz. After you press REV the transceiver
is set to receive on 147.54 MHz and transmit on 146.94 MHz.

This feature is useful if you want to determine whether you are close 
enough to another station to communicate on a simplex frequency.  While 
the other station is transmitting, reverse the frequencies.  If you can 
still hear the other station, you are hearing their signal directly and 
you do not need to use the repeater.

Memory Operation

Your transceiver has 10 standard memory locations that you can use to 
store frequencies for quick access.  You can also store other settings for 
each memory location, such as the repeater offset and the CTCSS tones.

Storing A Transmit/Receive Frequency

1.  Select the frequency you want to store by using the tuning control or
    UP/DN.

2.  If desired, select an offset frequency, offset direction, and CTCSS
    frequency for the selected frequency (see "Setting the Repeater Offset
    Frequency" above and "Continuous Tone Coded Squelch System Features"
    in Faxback Doc. # 60181).

3.  Press F + MS.  A memory location appears and flashes if empty.  To
    select a different memory location, repeatedly press UP/DN or rotate
    the tuning control.

4.  Press MR.  The transceiver stores the selected settings in the memory
    location.

5.  Press VFO to exit the memory mode.

Recalling Memories

1.  Press MR so a memory location number appears. 

2.  Press UP or DN or rotate the tuning control to select the desired
    memory location.

3.  Press VFO to return to the VFO mode.

Using The Calling-Frequency Memory

The calling-frequency memory location lets you quickly jump to a specific 
programmed frequency at any time.  The default calling frequency is 146.52 
MHz. You can store a different frequency into memory as well as other 
settings associated with that frequency, such as the repeater offset and 
CTCSS tone.

1.  Select the desired calling frequency using UP/DN or the tuning control

2.  Press F + MR (MS).  A memory location and ME appear.

3.  Rotate the tuning control or repeatedly press UP or DN until C appears 
    in the memory location area on the display. 

4.  Press MR (MS).  C flashes.

5.  Press MR (MS) again to store the selected frequency. 

6.  Press VFO (T-SQ) to return to the VFO mode. 

To enable the calling frequency, press CALL at any time.  The transceiver 
immediately tunes to that frequency with the settings you programmed.  To 
exit the calling frequency mode, press VFO (T-SQ).

Scanning Operation

Scanning For Active Frequencies

1.  To search for activity on a frequency, press SCAN (PRI). SCAN appears.
    The transceiver begins to scan up or down the full frequency range.
    The transceiver stops on each active frequency for 5 seconds if
    squelch is on.  If squelch is off, the transceiver stops on each
    location for about 1 second.

2.  To change the scanning direction, press UP or DN.

3.  To stop on a frequency or to stop scanning completely, press SCAN 
    again.

Scanning Standard Memory Locations

1.  Press MS (MR) then SCAN.  The transceiver scans all memory locations
    except empty locations.

2.  To change the scanning direction, press UP or DN.

3.  To stop scanning, press SCAN again.

(BR EB 6/14/00)

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